In my opinion you should try both and see what compliments your style of training.

I personally try to find something that is not so similar. In Aikido we didn't do much ground fighting, so I loved BJJ or Jujitsu. You have to remember that most arts stem from Jujitsu, even Judo. Judo is the Jujitsu in a different form.

I personally would go with Jujitsu because it has more to offer than Judo, depending on the teacher. What is noce about Judo is that you get to compete, but most Jujitsu practitioners also compete.

On a daily basis my classes compete against one another and use the tehcniques I teach them.

Anyways, either way, you won't go wrong. It all depends on what "you" want.